Ever since the arrival of the high-speed turbo-generator, the design of the rotor shaft has been subject to frequent changes independent of the usual attempts to improve its performance. A paramount question is whether it is safe to manufacture the rotor shaft with or without an axial test bore. After a series of rotor failures between the years 1925 and 1930, the question seemed to be settled with the acceptance of the axial bore as the standard procedure. The arrival of new test methods, different approaches in stress analysis, and improved steel types seem to demand a new revision. This paper contributes to the task by presenting opinions and experiences of German and British manufacturers.